Sept. 24-25, 2015: A group of doctors led by Dr. Mona Hanna-Attisha of Hurley Medical Center in Flint urges the city to stop using the Flint River for water after finding high levels of lead in the blood of children. State regulators insist the water is safe.Here is how this played out:
In August, Hanna-Attisha looked back at the lead tests of 1,750 children taken at a local hospital. She and colleagues released the results at a news conference in September.Her findings:
“We found that when we compared lead levels before and after the [water] switch, the percentage of kids with lead poisoning doubled after the switch,” she said last week. “In some neighborhoods, it tripled. And it all correlated with where water lead levels were the highest.”And the state's response to her work:
State officials questioned the findings and accused Hanna-Attisha of causing unnecessary hysteria. The state has since agreed that her data were accurate.Let's look at her work and judge it for what it shows.
What's interesting here is that she asked a question that should have been obvious to the MDHHS. Was there a difference between children's blood-lead levels (BLL) before the water change and after. And more specifically, in zip codes where the leaching of lead would most likely take place.
You can look at her presentation here. I am going to showjust her methodology and findings below.
First, her methodology:
She looked at the same period of time, pre-switch and post-switch. Was there a statistical difference between the period pre-switch and the same period post-switch?
Her analysis of the BLL data pre and post-switch shows affirmative. Before the switch 2.1% of the children in those zip codes in Flint had elevated BLL. After the switch it was 4%. That's a pretty good indication that the water is the culprit.
But wait a minute. Maybe its not the water and something else going on! Okay, fair question. How about we look at the children in that immediate area, but not in the zip codes where they used Flint water. If we see an increase in their elevated BLL then we can rule the water out as a soul source contributer. Does that sound reasonable?
No statistical change. What happens if we look at the BLL of children where Marc Edwards found elevated levels of lead above 15 ppb in the tap water samples they took? We'll call that data "High-water lead."
Putting it all together we get this:
Just in case you have had enough of the "golly we goofed" quotes, let's look at this talking point prepared in November 18, 2015 by the MDHHS:
And y'all never saw a reason for this level of testing while all this was going on?
But you did see a reason to question Hanna-Attisha's data on September 25th, correct? From an email for Gerlyn Lasher with MDHHS to the Governor's chief of staff Dennis Muchmore:
Notice how he put the quotes around the word data?
On October 2nd we get this statement from MDHHS Director Nick Lyon in the Governor's press release:
State health experts said there has been an increase in elevated childhood blood lead levels in some specific communities. Initial analysis of MDHHS data found that blood lead levels of children in Flint have followed an expected seasonal trend. While this analysis for Flint as a whole remains true, a comprehensive and detailed review brealking down data by ZIP codes with the city revealed that MDHHS data is consistent with a study presented recently by Hurley Children's Hospital.Look everyone, we found the same thing! Dr. Lyon continues:
"While we cannot conclusively say that the water source change is the sole cause of the increase, this analysis supports our efforts as we take active steps to reduce all potential lead exposures in Flint,"Dude, give it up...its the water.
Let's take a look at Marc Edwards' data next.
Next post: Flint Water: A Political Football. Part 10
